The present disclosure relates generally to welding systems and welding wire feed systems, and more particularly, to systems and methods for producing a regulated DC supply voltage from a variable AC source voltage.
Many types of welding systems, such as metal inert gas (MIG) welding, utilize continuously fed consumable wire from a welding torch during a welding operation. A wire feed motor is responsible for maintaining a continuous wire feed to the welding operation even when system demands require the motor torque to increase. Common factors such as wire diameter, wire type, drive roll type, drive roll tension, wire spool tension, torch cable length, and torch cable orientation may contribute to an increase in the motor torque requirement. Additionally, factors associated with the way a user sets up the wire feed system, such as positioning the wire feeder in a location remotely located from the primary power source, applying high drive roll tension, increasing cable length, and so forth can impact the motor torque requirement.
The voltage necessary to drive the motor and maintain the necessary motor torque is derived from a DC voltage supply, which is generated from a variable AC source voltage. Traditionally, the DC voltage supply is unregulated, and the magnitude of the unregulated DC voltage supply is directly dependent on the magnitude of the input AC source voltage. As the magnitude of the AC input supply at the wire feeder is reduced, the DC supply voltage available to the motor is also reduced. When the magnitude of the DC supply voltage falls below the requirement to maintain desired wire feed speed, the wire feed drive system no longer continually outputs the desired amount of wire. Accordingly, it is now recognized that a regulated, stable DC supply voltage is necessary for optimal wire feed motor performance.